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1.
Braz J Med Biol Res ; 53(4): e9200, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32267309

RESUMO

The consumption of alcoholic beverages influences carbohydrate and lipid metabolism, although it is not yet clear whether metabolism during physical exercise at different intensities is also affected. This was the objective of the present study. Eight young and healthy volunteers performed a treadmill test to identify the running speed corresponding to a lactate concentration of 4 mM (S4mM). At least 48 h later, they were subjected to two experimental trials (non-alcohol or alcohol) in which they performed two 1-km running sessions at the following intensities: 1) S4mM; 2) 15% above S4mM. In both trials, blood lactate, triglycerides, and glucose concentrations were measured before and after exercise. The acute alcohol intake increased triglycerides, but not lactate concentration under resting conditions. Interestingly, alcohol intake enhanced the exercise-induced increase in lactate concentration at the two intensities: S4mM (non-alcohol: 4.2±0.3 mM vs alcohol: 4.8±0.9 mM; P=0.003) and 15% above S4mM trial (P=0.004). When volunteers ingested alcohol, triglycerides concentration remained increased after treadmill running (e.g., at S4mM - at rest; non-alcohol: 0.2±0.5 mM vs alcohol: 1.3±1.3 mM; P=0.048). In contrast, glucose concentration was not modified by either alcohol intake, exercise, or their combination. We concluded that an acute alcohol intake changed lactate and lipid metabolism without affecting blood glucose concentration. In addition, the increase in lactate concentration caused by alcohol was specifically observed when individuals exercised, whereas augmented triglycerides concentration was already observed before exercise and was sustained thereafter.


Assuntos
Consumo de Bebidas Alcoólicas/sangue , Bebidas Alcoólicas/análise , Glicemia/metabolismo , Etanol/metabolismo , Ácido Láctico/sangue , Resistência Física/efeitos dos fármacos , Adulto , Desempenho Atlético/fisiologia , Glicemia/análise , Teste de Esforço , Humanos , Masculino , Resistência Física/fisiologia , Triglicerídeos/sangue , Adulto Jovem
2.
J Int Soc Sports Nutr ; 16(1): 47, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31660991

RESUMO

BACKGROUND: TeaCrine® is the synthetic version to naturally occurring theacrine (1, 3, 7, 9-tetramethyluric acid) found in the leaves of Camellia kucha tea plants. A few studies have examined the effects of TeaCrine® on cognitive perception, but no research exists examining its effects on resistance exercise performance. The purpose of this study was to determine the efficacy of TeaCrine®, a caffeine-like compound, on maximal muscular strength, endurance, and power performance in resistance-trained men. METHODS: Twelve resistance-trained men participated in a randomized, double-blind, cross-over designed study. Each participant performed one-repetition maximum (1RM) bench press, 1RM squat, bench press repetitions to failure (RTF) at 70% 1RM, squat RTF at 70% 1RM, and 2-km rowing time trial 90 min after consumption of: (1) Caffeine 300 mg (CAFF300); (2) TeaCrine® 300 mg (TEA300); (3) TeaCrine® + Caffeine (COMBO; 150 mg/150 mg); (4) Placebo 300 mg (PLA). Power and velocity were measured using a TENDO Power Analyzer. Visual analogue scales for energy, focus, motivation to exercise, and fatigue were administered at baseline and 90 min post-treatment ingestion (pre-workout). Rating of perceived exertion was assessed after bench press RTF and squat RTF. RESULTS: There were no differences between groups for 1RM, RTF, and power in the bench press and squat exercises. Only CAFF300 resulted in significant increases in perceived energy and motivation to exercise vs. TEA300 and PLA (Energy: + 9.8%, 95% confidence interval [3.3-16.4%], p < 0.01; + 15.3%, 95% CI [2.2-28.5%], p < 0.02; Motivation to exercise: + 8.9%, 95% CI [0.2-17.6%], p = 0.04, + 14.8%, 95% CI [4.7-24.8%], p < 0.01, respectively) and increased focus (+ 9.6%, 95% CI [2.1-17.1%], p = 0.01) vs. TEA300, but there were no significant differences between CAFF300 and COMBO (Energy + 3.9% [- 6.9-14.7%], Focus + 2.5% [- 6.3-11.3%], Motivation to exercise + 0.5% [- 11.6-12.6%]; p > 0.05). CONCLUSION: Neither TEA300, CAFF300, COMBO, or PLA (when consumed 90 min pre-exercise) improved muscular strength, power, or endurance performance in resistance-trained men. Only CAFF300 improved measures of focus, energy, and motivation to exercise.


Assuntos
Cafeína/farmacologia , Força Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/farmacologia , Resistência Física/efeitos dos fármacos , Ácido Úrico/análogos & derivados , Adulto , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Treinamento de Resistência , Ácido Úrico/farmacologia , Adulto Jovem
3.
Nutrients ; 11(9)2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31492050

RESUMO

BACKGROUND: this study examined the effects of caffeine supplementation on anaerobic performance, neuromuscular efficiency and upper and lower extremities fatigue in Olympic-level boxers. METHODS: Eight male athletes, members of the Spanish National Olympic Team, were enrolled in the study. In a randomized double-blind, placebo-controlled, counterbalanced, crossover design, the athletes completed 2 test sessions after the intake of caffeine (6 mg·kg-1) or placebo. Sessions involved initial measures of lactate, handgrip and countermovement jump (CMJ) performance, followed by a 30-seconds Wingate test, and then final measures of the previous variables. During the sessions, electromiography (EMG) data were recorded on the gluteus maximus, biceps femoris, vastus lateralis, gastrocnemius lateral head and tibialis anterior. RESULTS: caffeine enhanced peak power (6.27%, p < 0.01; Effect Size (ES) = 1.26), mean power (5.21%; p < 0.01; ES = 1.29) and reduced the time needed to reach peak power (-9.91%, p < 0.01; ES = 0.58) in the Wingate test, improved jump height in the CMJ (+2.4 cm, p < 0.01), and improved neuromuscular efficiency at peak power in the vastus lateralis (ES = 1.01) and gluteus maximus (ES = 0.89), and mean power in the vastus lateralis (ES = 0.95) and tibialis anterior (ES = 0.83). CONCLUSIONS: in these Olympic-level boxers, caffeine supplementation improved anaerobic performance without affecting EMG activity and fatigue levels in the lower limbs. Further benefits observed were enhanced neuromuscular efficiency in some muscles and improved reaction speed.


Assuntos
Boxe , Cafeína/administração & dosagem , Suplementos Nutricionais , Contração Muscular/efeitos dos fármacos , Fadiga Muscular/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Substâncias para Melhoria do Desempenho/administração & dosagem , Resistência Física/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Músculo Esquelético/fisiologia , Fatores de Tempo , Adulto Jovem
4.
J Ethnopharmacol ; 245: 112119, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31376516

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Risk of anterior cruciate ligament is a persistent and severe problem in athletes owing to strenuous exercise-induced lower-body injury. Tendon of deer liquid (TD) a familiar traditional Chinese medicine, has been used for strengthening the bones and muscles. AIM OF THE STUDY: In this study, we seek to demonstrate the application of TD in improving endurance exercise performance and reducing the risk of endurance training injury for free boxing players. MATERIALS AND METHODS: Sixteen male free boxing players were randomly assigned to the TD and placebo groups. Body composition, clinical biochemistry profiles, kinematic and physiology exercise tests were evaluated at 2 time points - pre-supplementation (pre-) and after 6 weeks post-supplementation (post-). RESULTS: TD group exhibited significant increase in levels of serum total protein (TP) compared to the placebo group after a 6-week supplementation. Following the treadmill test, serum glucose and maximal oxygen consumption (VO2 max) levels were increased in the TD group. In the endurance test consisting of 200 counts of drop vertical jumps (DVJs), subjects in the TD group also showed an increase in vertical jump height and reduced risk of musculoskeletal system injuries. CONCLUSIONS: TD supplementation leads to better physiological adaptation in free boxing players and has the potential for use as a nutrient supplement toward a variety of benefits for endurance athletes.


Assuntos
Boxe/fisiologia , Misturas Complexas/farmacologia , Cervos , Resistência Física/efeitos dos fármacos , Tendões , Adulto , Animais , Glicemia/efeitos dos fármacos , Proteínas Sanguíneas/análise , Método Duplo-Cego , Humanos , Masculino , Medicina Tradicional Chinesa , Consumo de Oxigênio , Adulto Jovem
5.
Nutrients ; 11(8)2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31443220

RESUMO

BACKGROUND: The main goal of this study was to assess the acute effects of the intake of 9 and 11 mg/kg/ body mass (b.m.) of caffeine (CAF) on maximal strength and muscle endurance in athletes habituated to caffeine. METHODS: The study included 16 healthy strength-trained male athletes (age = 24.2 ± 4.2 years, body mass = 79.5 ± 8.5 kg, body mass index (BMI) = 24.5 ± 1.9, bench press 1RM = 118.3 ± 14.5 kg). All participants were habitual caffeine consumers (4.9 ± 1.1 mg/kg/b.m., 411 ± 136 mg of caffeine per day). This study had a randomized, crossover, double-blind design, where each participant performed three experimental sessions after ingesting either a placebo (PLAC) or 9 mg/kg/b.m. (CAF-9) and 11 mg/kg/b.m. (CAF-11) of caffeine. In each experimental session, participants underwent a 1RM strength test and a muscle endurance test in the bench press exercise at 50% 1RM while power output and bar velocity were measured in each test. RESULTS: A one-way repeated measures ANOVA revealed a significant difference between PLAC, CAF-9, and CAF-11 groups in peak velocity (PV) (p = 0.04). Post-hoc tests showed a significant decrease for PV (p = 0.04) in the CAF-11 compared to the PLAC group. No other changes were found in the 1RM or muscle endurance tests with the ingestion of caffeine. CONCLUSION: The results of the present study indicate that high acute doses of CAF (9 and 11 mg/kg/b.m.) did not improve muscle strength nor muscle endurance in athletes habituated to this substance.


Assuntos
Atletas , Cafeína/administração & dosagem , Café , Comportamento Alimentar , Força Muscular/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Adulto , Cafeína/efeitos adversos , Estudos Cross-Over , Método Duplo-Cego , Humanos , Masculino , Polônia , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
6.
J Strength Cond Res ; 33(9): 2330-2337, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31306390

RESUMO

Hoffman, JR, Hoffman, MW, Zelicha, H, Gepner, Y, Willoughby, DS, Feinstein, U, and Ostfeld, I. The Effect of 2-Weeks of Inactivated Probiotic Bacillus coagulans on Endocrine, Inflammatory and Performance Responses During Self-Defense Training in Soldiers. J Strength Cond Res 33(9): 2330-2337, 2019-The effect of 2 weeks of inactivated Bacillus coagulans (iBC) ingestion on performance and inflammatory cytokines was examined during a self-defense course in soldiers. Sixteen male soldiers were randomly assigned to either iBC (n = 8) or placebo (PL; n = 8) in this double-blind study. Participants were garrisoned on base and participated in the same training tasks. Assessments were conducted in a single day before (PRE) and after the supplementation period (POST). During each testing session, participants were assessed for vertical jump power (VJP), muscle endurance, simulated casualty drag, and 2 100-m shuttle runs. Resting blood measures for testosterone, cortisol, creatine kinase, and inflammatory cytokines were also assessed. Mann-Whitney analysis of change (Δ) scores indicated no significant change (p's > 0.05) in any of the performance or blood variables. However, a trend (p = 0.089) was noted in the Δ score for VJP in iBC compared with PL. In addition, trends were observed in the change in IL-10 (p = 0.057) and IFNγ (p = 0.057). Magnitude based inferential analysis indicated that changes in VJP and simulated casualty drag were likely beneficial (90.7 and 80.4% likelihood effect, respectively) for iBC. In addition, iBC supplementation very likely augmented IL-10 concentrations, but was possibly negative for changes in IL-6, and likely negative for changes in TNFα and IFNγ. Changes in all other performance and blood markers were unclear. Results indicated that 2 weeks of iBC supplementation appeared to be beneficial for maintaining power and short-term speed performance, while attenuating the inflammatory response during intense training in a military self-defense course.


Assuntos
Bacillus coagulans , Citocinas/sangue , Exercício Físico/fisiologia , Artes Marciais/fisiologia , Militares , Probióticos/farmacologia , Creatina Quinase/sangue , Método Duplo-Cego , Humanos , Hidrocortisona/sangue , Inflamação/sangue , Interferon gama/sangue , Interleucina-10/sangue , Interleucina-6/sangue , Israel , Masculino , Artes Marciais/educação , Força Muscular/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Corrida , Testosterona/sangue , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
7.
Pak J Pharm Sci ; 32(3): 1011-1018, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31278714

RESUMO

Irpex lacteus is a white rot basidiomycete proposed for a wide spectrum of biotechnological applications. However, few studies examined its effects on exercise performance and physical fatigue. The present study evaluated the potential beneficial effects of I. lacteus extract (ILE) on physical fatigue in mice. Anti-fatigue activities of ILE were evaluated in Kunming mice using the forced swim test, rotating rod and forced running test. Serum and liver biochemical parameters were determined by an autoanalyzer and commercially available kits. Seven-day ILE administration at doses of 0.04, 0.2 and 1.0g/kg failed to influence mouse horizontal and vertical movement indicating its safety on the central nervous system. Compared with normal mice, ILE significantly increased persistent period during rotating rod and swimming tests, and reduced shock times in forced running test. Additionally, ILE resulted in 23.4% and 64.5% increments on adrenocorticotropic hormone and cortisol levels in serum. Compared with normal mice, and 209.0% increment on adenosine triphosphate level in liver (up to 2.5 mmol/gHb) were noted in ILE-treated mice. Moreover, ILE increased the level of super oxide dismutase and reduced the level of malondialdehyde in the liver suggesting its antioxidant activity. Data obtained from western bolt suggests that ILE-improved endurance capacity is mainly acquired through activating 5'-AMP-activated protein kinase (AMPK). ILE enhanced the endurance capacity of mouse by an elevation of antioxidant at least partially associated with AMPK pathway. Our data highlight the potential of I. lacteus as an antioxidant in the treatment of fatigue-related diseases.


Assuntos
Fadiga/tratamento farmacológico , Polissacarídeos Fúngicos/farmacologia , Polyporales/química , Proteínas Quinases Ativadas por AMP/metabolismo , Trifosfato de Adenosina/metabolismo , Hormônio Adrenocorticotrópico/metabolismo , Animais , Comportamento Animal/efeitos dos fármacos , Corticosterona/metabolismo , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Fadiga/metabolismo , Feminino , Polissacarídeos Fúngicos/química , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Malondialdeído/metabolismo , Camundongos , Resistência Física/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Teste de Desempenho do Rota-Rod , Superóxido Dismutase/metabolismo , Natação
8.
Life Sci ; 232: 116508, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31278948

RESUMO

AIM: Fluoxetine, one of the first newer SSRI antidepressant, is an extremely popular treatment for depression that could improve mental health problems. Many recent studies have suggested that SSRI have potential beneficial effects on skeletal muscle tissue. MAIN METHOD: We evaluated the potential beneficial effects of oral fluoxetine (18 mg/kg/day for 6 weeks) on muscle performance, after 6 weeks of physical exercise on treadmill. Male mice were randomly assigned to four groups (n = 12 per group) for treatment. Each group received treatment with following specifications: 1) no exercise with vehicle treatment (SED-S); 2) no exercise with fluoxetine treatment (SED-F); 3) exercise with vehicle treatment (EX-S); and 4) exercise with fluoxetine treatment (EX-F). Exercise performances were assessed based on the exhaustive running time and forelimb grip strength, anxious behavior by elevated plus-maze and open-field tests. Mitochondrial enzymes activity and ROS production were measured in the gastrocnemius and soleus muscles. KEY FINDING: Fluoxetine treatment had a significant effect on maximal aerobic capacity in mice without exercise, but more significant effects on gripping strength and anxiety when combined with exercise training, e.g. increased strength and decreased anxiety. SIGNIFICANCE: Fluoxetine treatment and exercise stimulation also had synergistic effects on strength and increased mitochondrial activity, cellular oxidative and antioxidant capacity in two different muscles.


Assuntos
Fluoxetina/farmacologia , Esforço Físico/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Oxirredução , Estresse Oxidativo , Condicionamento Físico Animal/fisiologia , Resistência Física/efeitos dos fármacos
9.
J Med Food ; 22(9): 944-951, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31339799

RESUMO

We developed low temperature-aged garlic (LTAG) to remove its unique and spicy flavor and evaluated the anti-fatigue properties of LTAG against exercise-induced fatigue in mice. In the results, the treadmill running time to exhaustion in the mice fed LTAG was prolonged compared with the control. There was significant difference in blood parameters of glucose, lactate, lactate dehydrogenase (LDH), and free fatty acid (FFA) concentration between the LTAG-fed mice and the control. In addition, LTAG effectively increased the content of glycogen and creatine kinase and the activity of antioxidant enzymes in the muscle. The mechanism underlying the anti-fatigue activity of LTAG is hypothesized to involve increase in postexercise tissue glycogen accumulation to improve the aerobic and anaerobic exercise capacity. LTAG may have an ergogenic effect on endurance exercise while decreasing the levels of FFA, LDH, and lactate, which are associated with the anti-fatigue effect. Thus, LTAG has potential as a pharmacological anti-fatigue agent.


Assuntos
Fadiga/tratamento farmacológico , Alho/química , Resistência Física/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Animais , Temperatura Baixa , Creatina Quinase/metabolismo , Suplementos Nutricionais/análise , Exercício Físico , Fadiga/sangue , Fadiga/fisiopatologia , Ácidos Graxos não Esterificados/sangue , Glicogênio/metabolismo , Humanos , L-Lactato Desidrogenase/sangue , Ácido Láctico/sangue , Masculino , Camundongos , Camundongos Endogâmicos ICR , Músculo Esquelético/metabolismo
10.
Can J Physiol Pharmacol ; 97(9): 857-862, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31251888

RESUMO

Acute physical exercise increases reactive oxygen species in skeletal muscle, leading to tissue damage and fatigue. Molecular hydrogen (H2) acts as a therapeutic antioxidant directly or indirectly by inducing antioxidative enzymes. Here, we examined the effects of drinking H2 water (H2-infused water) on psychometric fatigue and endurance capacity in a randomized, double-blind, placebo-controlled fashion. In Experiment 1, all participants drank only placebo water in the first cycle ergometer exercise session, and for comparison they drank either H2 water or placebo water 30 min before exercise in the second examination. In these healthy non-trained participants (n = 99), psychometric fatigue judged by visual analogue scales was significantly decreased in the H2 group after mild exercise. When each group was divided into 2 subgroups, the subgroup with higher visual analogue scale values was more sensitive to the effect of H2. In Experiment 2, trained participants (n = 60) were subjected to moderate exercise by cycle ergometer in a similar way as in Experiment 1, but exercise was performed 10 min after drinking H2 water. Endurance and fatigue were significantly improved in the H2 group as judged by maximal oxygen consumption and Borg's scale, respectively. Taken together, drinking H2 water just before exercise exhibited anti-fatigue and endurance effects.


Assuntos
Água Potável/química , Fadiga/psicologia , Hidrogênio , Resistência Física/efeitos dos fármacos , Adulto , Idoso , Método Duplo-Cego , Fadiga/metabolismo , Feminino , Humanos , Hidrogênio/metabolismo , Masculino , Pessoa de Meia-Idade , Placebos , Psicometria , Adulto Jovem
11.
Nutr. hosp ; 36(3): 698-705, mayo-jun. 2019. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-184570

RESUMO

Introducción: la beta-alanina (BA) es una de las ayudas ergogénicas más utilizadas actualmente por deportistas, pero la mayoría de los estudios centran su investigación en la suplementación prolongada. Objetivos: determinar el efecto agudo de la suplementación con BA sobre una prueba de tiempo límite (PTL) a velocidad aeróbica máxima (VAM) en atletas de resistencia. Material y método: once atletas de resistencia (VO2máx 61,6 ± 9,5 mLO2·kg-1·min-1) fueron parte del estudio. El diseño fue doble ciego, cruzado intrasujeto, y la suplementación de BA fue de 30 mg·kg-1 o placebo (PL) 60 minutos antes de completar una PTL. Las variables fueron: tiempo y distancia en la PTL y concentraciones de lactato ([La]) postesfuerzo en los minutos 1, 3, 5, 7 y 9. Para el análisis se utilizó una prueba t de Student y el tamaño del efecto (TE) se realizó mediante la prueba d de Cohen. Resultados: el tiempo en la PTL evidenció diferencias significativas entre la BA y PL (p = 0,047; TE = 0,48). No se observaron diferencias significativas en distancia entre ambos grupos (p = 0,071; TE = 0,48) y las [La] evidenciaron diferencias significativas entre ambos grupos en los minutos 3, 5 y 7, respectivamente (p < 0,05). Conclusión: la suplementación aguda con BA evidenció aumentos significativos en el tiempo de ejecución en la PTL a intensidades correspondientes a VAM. Por lo anterior, la suplementación aguda con BA es una ayuda ergogénica que podría ser considerada por los atletas de resistencia para aumentar el rendimiento deportivo


Introduction: the beta-alanine (BA) is one of the ergogenic aid most used by athletes, but the majority of the studies center the research on chronic supplementation. Objectives: to determine the acute effect of BA supplementation on a limited time test (LTT) at maximum aerobic speed (MAS) on endurance athletes. Material and method: eleven endurance athletes (VO2max 61.6 ± 9.5 mLO2·kg-1·min-1) were part of the study. The study consisted of a double-blind, cross-over intra-subject design, and the BA supplementation was 30 mg·kg-1 or placebo (PL) 60 minutes before completing a LTT. The variables were: time and distance in LTT, and post-effort lactate concentrations ([La]) in minutes 1, 3, 5, 7, and 9. The Student's t test was used for the analysis and the size of the effect (SE) was measured through Cohen's d test. Results: the time on LTT showed significant differences between BA and PL (p = 0.047; SE = 0.48). No significant differences were seen between both groups (p = 0.071; SE = 0.48), and [La] showed significant differences between both groups in minutes 3, 5 and 7, respectively (p < 0.05). Conclusion: acute supplementation with BA showed a significant increase in the execution time in LTT in the intensities connected to MAS. Hence, acute supplementation with BA is an ergogenic aid that could be considered by resistance athletes in order to increase the athletic performance


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Adulto , beta-Alanina/administração & dosagem , Alimentos para Praticantes de Atividade Física , Resistência Física/efeitos dos fármacos , beta-Alanina/metabolismo , Método Duplo-Cego , Placebos , Chile , Índice de Massa Corporal , Peso-Estatura/fisiologia , Consumo de Oxigênio
12.
Nutr Hosp ; 36(3): 698-705, 2019 Jul 01.
Artigo em Espanhol | MEDLINE | ID: mdl-31144977

RESUMO

Introduction: Introduction: the beta-alanine (BA) is one of the ergogenic aid most used by athletes, but the majority of the studies center the research on chronic supplementation. Objectives: to determine the acute effect of BA supplementation on a limited time test (LTT) at maximum aerobic speed (MAS) on endurance athletes. Material and method: eleven endurance athletes (VO2max 61.6 ± 9.5 mLO2•kg-1•min-1) were part of the study. The study consisted of a double-blind, cross-over intra-subject design, and the BA supplementation was 30 mg•kg-1 or placebo (PL) 60 minutes before completing a LTT. The variables were: time and distance in LTT, and post-effort lactate concentrations ([La]) in minutes 1, 3, 5, 7, and 9. The Student's t test was used for the analysis and the size of the effect (SE) was measured through Cohen's d test. Results: the time on LTT showed significant differences between BA and PL (p = 0.047; SE = 0.48). No significant differences were seen between both groups (p = 0.071; SE = 0.48), and [La] showed significant differences between both groups in minutes 3, 5 and 7, respectively (p < 0.05). Conclusion: acute supplementation with BA showed a significant increase in the execution time in LTT in the intensities connected to MAS. Hence, acute supplementation with BA is an ergogenic aid that could be considered by resistance athletes in order to increase the athletic performance.


Assuntos
Atletas , Desempenho Atlético , Suplementos Nutricionais , Resistência Física/efeitos dos fármacos , Corrida/fisiologia , beta-Alanina/farmacologia , Adolescente , Adulto , Limiar Anaeróbio/efeitos dos fármacos , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , Substâncias para Melhoria do Desempenho , Adulto Jovem
13.
J Strength Cond Res ; 33(6): 1653-1657, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31125326

RESUMO

Bastos-Silva, VJ, Prestes, J, and Geraldes, AAR. Effect of carbohydrate mouth rinse on training load volume in resistance exercises. J Strength Cond Res 33(6): 1654-1658, 2019-The aim of this study was to investigate the effect of carbohydrate (CHO) mouth rinse on training load volume (TLV-number of repetitions × load lifted [kg]) on 2 resistance exercises: leg press (LP) and bench press (BP). Twelve recreational resistance trained males were recruited. Subjects were assessed for 1 repetition maximum (1RM) and muscular endurance (ME) in LP and BP. Muscular endurance was determined by the maximum number of repetitions performed to volitional fatigue, with a load equal to 80% of 1RM. Exercises were performed on separate days (72 hours apart) under 3 experimental conditions: control (CONT), CHO (25 ml with 6.4% of maltodextrin), and placebo (juice without CHO [PLA]). Carbohydrate and PLA were used immediately before each exercise. There was no significant difference between conditions for the number of repetitions (CHO = 13.5 ± 4.8; PLA = 11.5 ± 4.4; CONT = 12.4 ± 4.4, p = 0.68) nor TLV (CHO = 2006.7 ± 825.2 kg; PLA = 1712.5 ± 772.9 kg; CONT = 1817.1 ± 672.6 kg, p = 0.99) in LP. However, CHO increased both repetitions (CHO = 8.2 ± 1.6; PLA = 7.1 ± 2.4; CONT = 6.8 ± 1.8, p = 0.002) and TLV (CHO = 557.1 ± 155.4 kg; PLA = 495.9 ± 206.1 kg; CONT = 476.1 ± 175.3 kg, p = 0.035) compared with CON in BP. Thus, a CHO mouth rinse increases BP performance in trained men, suggesting an interesting strategy to be used by experienced resistance training practitioners.


Assuntos
Antissépticos Bucais/farmacologia , Resistência Física/efeitos dos fármacos , Polissacarídeos/farmacologia , Treinamento de Resistência , Levantamento de Peso/fisiologia , Adulto , Teste de Esforço , Humanos , Masculino , Adulto Jovem
14.
Nutrients ; 11(4)2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30934886

RESUMO

The ergogenicity of caffeine on several exercise and sport situations is well-established. However, the extent of the ergogenic response to acute caffeine ingestion might greatly vary among individuals despite using the same dosage and timing. The existence of one or several individuals that obtained minimal ergogenic effects or even slightly ergolytic effects after caffeine intake (i.e., non-responders) has been reported in several previous investigations. Nevertheless, the concept non-responding to caffeine, in terms of physical performance, relies on investigations based on the measurement of one performance variable obtained once. Recently it has been suggested that correct identification of the individual ergogenic effect induced by caffeine intake requires the repeated measurement of physical performance in identical caffeine⁻placebo comparisons. In this communication, we present data from an investigation where the ergogenic effect of acute caffeine intake (3 mg/kg) was measured eight times over a placebo in the same individuals and under the same conditions by an incremental cycling test to volitional fatigue and an adapted version of the Wingate cycling test. The ergogenic response to caffeine varied from 9% to 1% among individuals, but all participants increased both cycling power in the incremental test and Wingate mean power at least three to eight times out of eight the caffeine⁻placebo comparisons. These data expand the suggestion of a minimal occurrence of caffeine non-responders because it shows that all individuals responded to caffeine when caffeine is compared to a placebo on multiple and repeated testing sessions.


Assuntos
Cafeína/farmacologia , Estimulantes do Sistema Nervoso Central/farmacologia , Resistência Física/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Adulto , Estudos Cross-Over , Fadiga , Humanos
15.
Eur J Appl Physiol ; 119(6): 1419-1429, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31030296

RESUMO

PURPOSE: To evaluate the effect of antioxidant supplementation on intense endurance exercise performance and the physiologic exercise response acutely and in early recovery. METHODS: Well-trained cyclists (n = 11, peak VO2: 69 ± 7 ml/min/kg) completed two identical standardized 20-min warm-up periods (WU-1 and WU-2) prior to two performance tests (PT) with a duration of ~ 4 min representing a qualifying (PT-1) and final race (PT-2) on the same day separated by 90 min. Subjects were supplemented orally with placebo (PLA) and N-acetyl cysteine (NAC; 20 mg/kg) before exercise in a double-blinded crossover design. RESULTS: Mean power during PT-1 did not differ (P = 0.39) between PLA (400 ± 44 W) and NAC (401 ± 44 W) as was the case during PT-2 with similar performance (P = 0.74) between PLA (401 ± 43 W) and NAC (400 ± 42 W). Subjective "readiness" was lowered by prior exhaustive exercise from PT-1 to PT-2 (P = 0.012) in both PLA and NAC. Plasma total antioxidant capacity was not affected by supplementation and prior exhaustive exercise (respective main effects: P = 0.83 and P = 0.19) which also was observed for peak VO2 at ~ 5 L/min (P = 0.84 and P = 0.30). In WU-1 and WU-2, both cycling economy at ~ 20% (P = 0.10 and P = 0.21) and plasma potassium at ~ 5 mmol/L (P = 0.46 and P = 0.26) were unaffected by supplementation and prior exercise. CONCLUSIONS: Athletes executing maximal efforts of a ~ 4-min duration twice daily, as seen in track cycling, appear to gain no benefit from oral NAC supplementation on acute and subsequent performance following short-term recovery. Moreover, well-trained cyclists exhibit rapid recovery from a single bout of intense endurance cycling.


Assuntos
Acetilcisteína/farmacologia , Ciclismo/fisiologia , Depuradores de Radicais Livres/farmacologia , Resistência Física/efeitos dos fármacos , Acetilcisteína/administração & dosagem , Adulto , Depuradores de Radicais Livres/administração & dosagem , Humanos , Masculino
16.
Nutrients ; 11(4)2019 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-31014016

RESUMO

The purpose of the present study was to examine characteristics of multi-ingredient pre-workout supplement (MIPS) users, their common patterns/habits of MIPS ingestion, and their associated feelings about the effectiveness and safety of this class of supplements. An online electronic survey was distributed through social media to assess self-reported supplementation practices and preferences among adult males and females who reported regular MIPS use. A total of 1045 individuals responded, with 872 of these individuals (males: n = 636, 72.9%; females: n = 233, 26.7%; mean ± SD; age = 27.7 ± 7.9 years; training age = 8.2 ± 7.3 years) completing the survey. The majority of respondents reported the length of current or past MIPS consumption as greater than one year (n = 630, 72.2%), with ingestion frequencies primarily of four (n = 210, 24.1%) or five (n = 212, 24.3%) days per week of training. In addition, the three most popular goals for ingesting MIPS were increased energy and focus (n = 776, 89.0%), muscular endurance (n = 325, 37.3%), and blood flow or "pump" (n = 322, 37.0%). Although most users reported ingesting one serving size with each use, 14% reported ingesting two or more, and 18% indicated they ingest MIPS more than once per day. Importantly, over half (54%) of the respondents reported experiencing side-effects following MIPS use, including skin reactions, heart abnormalities, and nausea. Females were more likely than males to experience these side effects, despite being less likely to consume two or more serving sizes per dose. Our findings also indicated that MIPS users should consume no more than the recommended serving size of a given supplement, as the potentially significant variability in the caffeine content of MIPS products is compounded as more doses are consumed. Furthermore, MIPS users should minimize the ingestion of other supplements which contain high levels of niacin and caffeine, as the concurrent consumption of such products may put users above the tolerable upper limits for these substances.


Assuntos
Suplementos Nutricionais , Exercício Físico , Fenômenos Fisiológicos da Nutrição Esportiva , Adulto , Desempenho Atlético , Coleta de Dados , Feminino , Humanos , Masculino , Resistência Física/efeitos dos fármacos , Treinamento de Resistência , Inquéritos e Questionários , Adulto Jovem
17.
Nutrients ; 11(4)2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30925733

RESUMO

The efficacy of pomegranate (Punica granatum) extract (PE) for improving performance and post-exercise recovery in an active population was equivocal in previous studies. In this study, a randomised, double-blinded, placebo-controlled, balanced, cross-over trial with two arms was conducted. Eligibility criteria for participants were as follows: male, amateur cyclist, with a training routine of 2 to 4 sessions per week (at least one hour per session). The cyclists (n = 26) were divided into treatment (PE) and placebo (PLA) groups for a period of 15 days. After physical tests, the groups were exchanged after a 14-day washout period. Exercise tests consisted of endurance bouts (square-wave endurance exercise test followed by an incremental exercise test to exhaustion) and an eccentric exercise drill. The objective was to assess the efficacy of PE in performance outcomes and post-exercise muscular recovery and force restoration after a prolonged submaximal effort. Twenty-six participants were included for statistical analysis. There was a statistically significant difference in total time to exhaustion (TTE)(17.66⁻170.94 s, p < 0.02) and the time to reach ventilatory threshold 2 (VT2)(26.98⁻82.55 s, p < 0.001), with greater values for the PE compared to the PLA group. No significant results were obtained for force restoration in the isokinetic unilateral low limb test. PE, after a prolonged submaximal effort, may be effective in improving performance outcomes at maximal effort and might help to restore force in the damaged muscles.


Assuntos
Ciclismo , Exercício Físico , Sucos de Frutas e Vegetais , Lythraceae , Resistência Física/efeitos dos fármacos , Adulto , Biomarcadores , Método Duplo-Cego , Humanos , Inflamação , Masculino , Fadiga Muscular , Músculo Esquelético/lesões , Músculo Esquelético/metabolismo
18.
Am J Physiol Endocrinol Metab ; 316(5): E956-E966, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30860879

RESUMO

The intestinal microbiome produces short-chain fatty acids (SCFAs) from dietary fiber and has specific effects on other organs. During endurance exercise, fatty acids, glucose, and amino acids are major energy substrates. However, little is known about the role of SCFAs during exercise. To investigate this, mice were administered either multiple antibiotics or a low microbiome-accessible carbohydrate (LMC) diet, before endurance testing on a treadmill. Two-week antibiotic treatment significantly reduced endurance capacity versus the untreated group. In the cecum acetate, propionate, and butyrate became almost undetectable in the antibiotic-treated group, plasma SCFA concentrations were lower, and the microbiome was disrupted. Similarly, 6-wk LMC treatment significantly reduced exercise capacity, and fecal and plasma SCFA concentrations. Continuous acetate but not saline infusion in antibiotic-treated mice restored their exercise capacity (P < 0.05), suggesting that plasma acetate may be an important energy substrate during endurance exercise. In addition, running time was significantly improved in LMC-fed mice by fecal microbiome transplantation from others fed a high microbiome-accessible carbohydrate diet and administered a single portion of fermentable fiber (P < 0.05). In conclusion, the microbiome can contribute to endurance exercise by producing SCFAs. Our findings provide new insight into the effects of the microbiome on systemic metabolism.


Assuntos
Acetatos/metabolismo , Ácidos Graxos Voláteis/metabolismo , Microbioma Gastrointestinal/fisiologia , Condicionamento Físico Animal , Resistência Física/fisiologia , Animais , Antibacterianos/farmacologia , Butiratos/metabolismo , Fibras na Dieta/metabolismo , Transplante de Microbiota Fecal , Microbioma Gastrointestinal/efeitos dos fármacos , Camundongos , Resistência Física/efeitos dos fármacos , Propionatos/metabolismo
19.
Nutrients ; 11(2)2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30736383

RESUMO

The natural polyphenols mangiferin and luteolin have free radical-scavenging properties, induce the antioxidant gene program and down-regulate the expression of superoxide-producing enzymes. However, the effects of these two polyphenols on exercise capacity remains mostly unknown. To determine whether a combination of luteolin (peanut husk extract containing 95% luteolin, PHE) and mangiferin (mango leave extract (MLE), Zynamite®) at low (PHE: 50 mg/day; and 140 mg/day of MLE containing 100 mg of mangiferin; L) and high doses (PHE: 100 mg/day; MLE: 420 mg/day; H) may enhance exercise performance, twelve physically active men performed incremental exercise to exhaustion, followed by sprint and endurance exercise after 48 h (acute effects) and 15 days of supplementation (prolonged effects) with polyphenols or placebo, following a double-blind crossover design. During sprint exercise, mangiferin + luteolin supplementation enhanced exercise performance, facilitated muscle oxygen extraction, and improved brain oxygenation, without increasing the VO2. Compared to placebo, mangiferin + luteolin increased muscle O2 extraction during post-exercise ischemia, and improved sprint performance after ischemia-reperfusion likely by increasing glycolytic energy production, as reflected by higher blood lactate concentrations after the sprints. Similar responses were elicited by the two doses tested. In conclusion, acute and prolonged supplementation with mangiferin combined with luteolin enhances performance, muscle O2 extraction, and brain oxygenation during sprint exercise, at high and low doses.


Assuntos
Antioxidantes/administração & dosagem , Suplementos Nutricionais , Exercício Físico/fisiologia , Luteolina/administração & dosagem , Desempenho Físico Funcional , Xantonas/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Voluntários Saudáveis , Humanos , Ácido Láctico/sangue , Masculino , Consumo de Oxigênio/efeitos dos fármacos , Resistência Física/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Corrida/fisiologia , Adulto Jovem
20.
PLoS One ; 14(2): e0211818, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30742658

RESUMO

The present study aimed to estimate the effect of endurance training, two doses of testosterone, and the combination of these stimuli on the level of the endothelial proteins claudin, occludin, JAM-1, VE-cadherin, ZO-1, ZO-2, and P-glycoprotein in rat spinal cords. Adult male Wistar rats were trained using a motor-driven treadmill for 6 weeks (40-60 min, 5 times per week) and/or were treated for 6 weeks with two doses of testosterone (i.m.; 8 mg/kg or 80 mg/kg body weight). Spinal cords were collected 48 hours after the last training cycle and stored at -80°C. The levels of selected proteins in whole tissue lysates of the spinal cord were measured by western blot. Testosterone-treated trained rats had significantly lower claudin levels than vehicle-treated trained rats. High doses of testosterone resulted in a significant decrease in claudin-5 in untrained rats compared to the control group. Both doses of testosterone significantly reduced occludin levels compared to those in vehicle-treated untrained rats. The JAM-1 level in the spinal cords of both trained and untrained animals receiving testosterone was decreased in a dose-dependent manner. The JAM-1 level in the trained group treated with high doses of testosterone was significantly higher than that in the untrained rats treated with 80 mg/kg of testosterone. VE-cadherin levels were decreased in all groups receiving testosterone regardless of endurance training and were also diminished in the vehicle-treated group compared to the control group. Testosterone treatment did not exert a significant effect on ZO-1 protein levels. Testosterone and/or training had no significant effects on ZO-2 protein levels in the rat spinal cords. Endurance training increased P-glycoprotein levels in the rat spinal cords. The results suggest that an excessive supply of testosterone may adversely impact the expression of endothelial proteins in the central nervous system, which, in turn, may affect the blood-brain barrier function.


Assuntos
Endotélio Vascular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Condicionamento Físico Animal , Resistência Física/efeitos dos fármacos , Medula Espinal , Testosterona/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Animais , Antígenos CD/biossíntese , Caderinas/biossíntese , Moléculas de Adesão Celular/biossíntese , Claudina-5/biossíntese , Relação Dose-Resposta a Droga , Masculino , Ratos , Ratos Wistar , Medula Espinal/química , Medula Espinal/metabolismo , Proteína da Zônula de Oclusão-1/biossíntese , Proteína da Zônula de Oclusão-2/biossíntese
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